Structural and lithological observations in a N-S traverse across Bremangerlandet, western Norway, demonstrate that the region is separated into two plates by the E-W-striking, S-dipping ductile-brittle Vetvika Shear Zone. The Vetvika Shear Zone places Caledonian high-grade gneisses, with a Precambrian protolith age of the lower plate, in tectonic contact with heterogeneous gneisses of the upper plate. The Vetvika Shear Zone is the uppermost part of the Nordfjord-Sogn Detachment Zone. A gently W-plunging stretching lineation within the S-dipping lower-plate augen gneisses is interpreted as having formed within a several kilometers thick ductile W-dipping extensional shear zone that has undergone later rotation around an E-W axis. A highly attenuated sequence of nappes occur structurally on top of a heterogeneous basement and cover quartzite of the upper plate. Pre-Caledonian structures are preserved locally in the gneissic upper plate basement. The nappes at Bremangerlandet are correlated with the Caledonian Middle and Upper Allochthons, representing Baltic/suspect and exotic terranes, respectively. One large and several medium- to small-scale, brittle, top-to-the-south extensional faults are superimposed on ductile contractional structures in the upper plate. Some of the extensional faults merge downward with the Vetvika Shear Zone. The contractional structures include E-W-trending folds and S-directed thrusts in the cover quartzite, and are superimposed on a pronounced W-E stretching lineation. Conjugate sets of fractures and faults related to E-W extension represent the youngest structures in the upper plate. The Old Red Sandstones (Devonian) of the Hornelen basin rest unconformably on top of extensionally faulted upper plate rocks on Bremangerlandet. The unconformity is partly faulted at Bremanger, and truncated by a regionally extensive late, brittle fault along the basin margin further east. This suggests a long-lived tectonic history for the Vetvika Shear Zone and its eastward continuation, with movement pre- and post-dating the filling of the collapse basin, possibly as an eastward migration of the break-away fault.